The present disclosure relates to a communication device that can communicate with the outside.
There are conventionally known communication devices, such as smartphones and tablet computers, that their users can carry around. These communication devices are compact, and are easy to lose. For example, they are often left behind in railroad vehicles and in buses.
For example, if a communication device passes into the hands of a stranger, there may arise an inconvenience of unauthorized use by the stranger. For this reason, some communication devices are furnished with a function for preventing unauthorized use by a stranger.
Such a conventional communication device, when operated, shoots the operator with a camera and performs face authentication and password authentication. Unless the face authentication and password authentication verify the operator as the legitimate owner of the communication device, it enters a locked state (a state in which it does not accept any operation by the operator). That is, when the stranger operates the communication device, it enters the locked state. This helps prevent unauthorized use of the communication device by the stranger.